This is sad. Extremely sad. I'm glad you're a strong hustler because some people would have become stray street kids because they're trying to escape from a toxic home.
Staunch MFM members you say? There lies a part of your answer. Report her to the church asap. Tell the pastor she respects the most about your situation and let them have a serious meeting with her.
I would have written her off completely but from what I can see (especially from the fact that she gave you 150,000 for your admission) is that she is angry that she singularly has to bear the responsibility of taking care of you. Your existence is a symbol of the mistake she made by being with your estranged father. I'll advise you to find another job, retake jamb and get the hell out of the house. I would also advise you to never repay her wicked outbursts with evil. She could have gotten rid of you guys when she was much younger but the fact that you're still alive and under her roof shows she still has a drop of mothers milk left in her. Just a drop but it's still there.
Ignore her as you usually do. Stay out of her way. Greet her and plan your exit strategy fast. You're not a child anymore and in some societies you'll be living on your own. I wish you the best and I pray that God blesses you and your siblings beyond your wildest imagination. And I pray he keeps your mother alive to see God's blessings upon you all.
Damn though. Some people really do have life tough!